Evaluation of cardiovascular autonomic dysfunction in symptomatic post COVID-19 patients

ABSTRACT

Background: The COVID-19 disease is known for its severe respiratory complications, however it was found to have some cardiovascular complication in post COVID-19 patients. The heart rate variability (HRV) is a non invasive, objective and reliable method for assessment of autonomic dysfunction in those recovered patients. Purpose(s) We aimed to evaluate the cardiac autonomic function by using valid HRV indices in subjects who recovered from mild to moderate acute COVID-19 but still symptomatic. Method(s) The study Group composed of 50 subjects with confirmed history of mild to moderate post COVID 19. All subjects underwent routine 2D echocardiography assessment in addition to 2D speckle tracking and 24 hours Holter monitoring for HRV analysis. Result(s) The mean age of the study population was 42+/-18 years, symptoms were reported as follows 27 (54%) had Dyspnea, 17 (34%) had palpitations, 7 (14%) had dizziness. Time domain parameters SDNN, SDANN and rMSSD were diminished with mean SDNN value being markedly impaired in 12 (24%) patient, while frequency domain parameters as assessed by LF/HF ratio with mean of 1.837 with 8% of patients being impaired. SDNN was significantly reduced in elderly patients (p=0.001), smokers (p=0.019) and hypertensive (p=0.016) and those complaining mainly of palpitation (p=0.006). SDNN was significantly reduced in patient with impaired LV diastolic function (p=0.009), in patients with reduced MAPSE (p=0.047), reduced TAPSE (p=0.00) and impaired Global longitudinal strain (0.000). Conclusion(s) Patients with post COVID-19 syndrome have abnormalities in the HRV which indicates some degree of dysfunction in the autonomic nervous system and consequently impaired parasympathetic function in this population, however this have been also correlating with subtle impairment of the left ventricular systolic function.We believe that this preliminary research can serve a starting point for future research in this direction.